Earnings Per Share (Tables)

3 Months Ended

Mar. 31, 2019

Earnings Per Share [Abstract]

Computation of Basic and Diluted Earnings per Share

	Three Months Ended
	March 31,
(in millions, except per share data)	2019		2018
Net income attributable to common shareholders	$	82.4	$	68.7
Average basic shares outstanding	59.8		59.7
Effect of dilutive stock options	0.9		1.3
Average diluted shares outstanding	60.7		61.0
Earnings per basic share	$	1.38	$	1.15
Earnings per diluted share	$	1.36	$	1.13